Using lymphocytes from normal individuals we have determined that helper cells function normally, as judged by their ability to proliferate, when in the presence of a much larger number of autologous lymphocytes of suppressor cell-surface phenotype. Since AIDS lymphocytes do not proliferate in response to microbial antigens even when substantial numbers of helper cells are present, an additional qualitative abnormality in their mononuclear cells must exist. We will pursue our preliminary observations that cells from the blood of patients with AIDS are activated to "spontaneously" suppress the proliferative responses to microbial antigens of lymphocytes from normal donors. In addition, by employing panning techniques that we previously have used successfully, we will negatively select subpopulations of lymphocytes from AIDS patients depleted of cells of helper surface phenotype, or suppressor phenotype, reassemble these populations in desired proportions on autologous monocytes, and determine their proliferative response. These experiments should help us to determine whether AIDS cells of helper surface phenotype can function normally in the absence of suppressor cells or whether the helper cells are qualitatively abnormal. We will continue to examine cell lines established from the blood of AIDS patients and the AIDS-related complex. Are viruses other than EBV present in lines of the B-cell lineage? If lines of T-cell lineage are established, what viruses will be present in these lines? What is the nature of the antigens on cell lines that are recognized by sera from patients with AIDS, as judged by fluorescent antibody and absorption techniques? (TT)